The Commercial Mobile Alert System (CMAS) was established by the Federal Communications Commission (FCC) to allow wireless service providers to send emergency alerts to their subscribers. Such alerts are initially intended to be in the form of text messages, but may also take the form of audio and video alerts. The CMAS network will allow emergency service agencies, such as the Federal Emergency Management Agency (FEMA), to accept and aggregate alerts from federal, state, and local emergency operations centers, and send the alerts over a secure interface to wireless providers. The wireless providers can then distribute the alerts to their customers.
While the FCC has proposed and adopted the network structure, technical requirements, and operating procedures for the CMAS, wireless service providers that participate in the CMAS must develop their own systems to receive alerts from FEMA and distribute them to their customers. Such systems must allow the wireless service providers to target individual geographical areas, such as counties, for distribution of emergency alerts.
There are currently three types of emergency alerts. Presidential Alerts that relate to national emergencies, Imminent Threat Alerts that relate to emergencies where life or property is at risk, such as hurricanes or tornadoes, and Child Abduction Emergency/AMBER Alerts that relate to missing or endangered children due to an abduction or runaway situation. Subscribers may be able to opt-out of receiving Imminent Threat and Child Abduction/AMBER alerts, but may not be permitted to opt-out of Presidential Alerts.